Continuous span floors have benefits of being able to span longer compared to simple span floors with the same joist section.  This does not come without cost: continuous span joists transfer vibration from one floor to the other along joist length.  In contrast simple span joist floors contain vibration within the loaded floor and effect on other parts of the structure is minimal.

There are many misconceptions on how to remedy continuous joist floor problems like: 1) Putting blocking or squash blocks at intermediate bearing.  This will not change vibration mode of the floors at all; the only benefit will be a better stabilization/holding of the joist at intermediate bearings, 2) Cutting top flange ( and web ) at the intermediate bearing, this will change vibration mode of the floors by preventing vibration transfer between the floors, but it will also increase vibration problems on both floors since simple span has higher deflection for the same load compared to the continuous span.  In addition to this, cutting the flange will invalidate floor design since the top flange at intermediate support is critical for joist moment capacity and this must not be done and 3) Added ceiling will help but to a lesser degree since added mass always reduces floor performance to a degree.

The best way to deal with continuous joist floor vibration problem is to reduce initial deflection under “footstep impact load” so that transfered vibration to the other floor is also reduced accordingly.

Engineered IBS 2000 bridging has been repeatedly proven to reduce deflection by 50+%, thus radically reducing vibration effect of footstep load.

Thus, continuous span vibration problems can never be totally eliminated; but with the installation of IBS 2000, they can be greatly reduced bringing floors to acceptable levels.

Luxor has recently posted a demonstration video showing the different performance between some common floor bridging products (blocking and conventional bridging) and IBS2000. Each one of the three test setups was subjected to a 450lb load (such as a common footstep load).

As seen in the video, IBS2000 delivered more than 5 times the performance of the nearest competitor! You can trust IBS2000 to fix any problem you might have with a bouncy floor.

Click here to view the video on You Tube.

“I have ceramic tiles on my floors and I actually had grout cracks in some of the floor areas.  We filled in the grout and in a few weeks, the grout cracked again.  Will the IBS 2000 help eliminate any future grout cracks?” 

Two things that you must look at: 1) are the joists deflecting or sagging a lot and 2) is there excessive vibration or bounce in the joists.  If you find that the joists are deflecting too much, then you must first lift or jack up the joists.  Then you can install the IBS 2000 bridging.  Luxor recommends that you use retrofit IBS units.  The IBS 2000 will structurally lock the joists together, stiffening up the floor system.  This will minimize joist movement. 

Please note that grout crack could have been caused by poor installation ( tile/mortar bed or floor system ), inadequate design ( was a wider o/c spacing used or a heavier dead load ) or subfloor issues ( excessive deflection of subfloor between joists ).